High to low gas flow regulator

ABSTRACT

A diaphragm operated regulator valve usable, e.g., for maintaining a preset gas pressure in a potable storage container, provides particularly effective at gas flow regulation as well as pressure regulation. The use of the word “fluid” as used herein can encompass both liquids and gasses. The valve includes a gas-balanced piston-tower diaphragm assembly that is freely supported, sealed, and operatively connected to a pressure-biasing adjustment. The diaphragm assembly permits axial movement relationships between valving channels or pathways, a valving-seal, and volume changes that take place in a low-pressure chamber. The valve 1) converts axial movement of the diaphragm into smooth transitional flow rates by varying the cross sectional areas of ingress and egress from an open valve position to a closed valve position and 2) has the ability to preset maximum flow rates.

CROSS REFERENCE TO A RELATED APPLICATION

This application claims the benefit of the filing date of the earlierU.S. Provisional Patent App. Ser. No. 60/165,893, filed Nov. 12, 1999 antitled High to Low Gas Flow Regulator.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a regulator valve for maintaining a designatedgas pressure at an output thereof, and more particularly to a regulatorvalve that maintains a preset gas pressure and a set maximum flow ratein a device such as a transportable container for potable liquids.

3. Discussion of the Related Art

Diaphragm operated regulator valves have been utilized to regulate theflow of compressed gas applied to a gas layer on top of liquids in astorage container and to other low pressure applications. The gas isnormally a non-flammable gas, such as carbon dioxide and/or nitrogen.One such regulator valve is disclosed in U.S. Pat. No. 5,238,021, datedAug. 24, 1993. In this valve, pressure flow is regulated via a diaphragmactuator. The diaphragm actuator is 1) relatively large, 2) very costlyto manufacture, and 3) unsuitable in some applications of portablestorage container operations. In addition, because regulator valves ofthis general type are no more than a poppet valve with a control spring,they cannot be changed to different flow rates without beingre-manufactured. They also move open abruptly from a fully losedposition to a fully-open position and, therefore, cannot transitionsmoothly from a closed position to an open position and cannot achieve aflow rate therethrough that is proportional to the amount of valveopening.

OBJECTS AND SUMMARY OF THE INVENTION

In accordance with the first aspect of the invention, a diaphragmoperated regulator valve for maintaining a preset gas pressure in apotable storage container is provided with a relatively small diameterdiaphragm and provides particularly effective at gas flow regulation aswell as pressure regulation. The use of the word “fluid” as used hereincan encompass both liquids and gasses.

The regulator valve is usable, e.g., as a potable fluid regulator valverated at low fluid pressures. The valve includes a gas-balancedpiston-tower diaphragm assembly that is freely supported, sealed, andoperatively connected to a pressure-biasing adjustment. The diaphragmassembly permits axial movement relationships between valving channelsor pathways, a valving-seal, and volume changes that take place in alow-pressure chamber. The valve 1) converts axial movement of thediaphragm into smooth transitional flow rates by varying the crosssectional areas of ingress and egress from an open valve position to aclosed valve position and 2) has the ability to preset maximum flowrates.

The axial movement and sealing of valving channels exposed to fluidpressure occurs generally as disclosed in, U.S. Pat. No. 5,645,192 andU.S. Pat. No. 6,109,485, both of which are incorporated by reference intheir entirety. This axial movement is the most important parameter indetermining the sensitivity or responsiveness of the regulator valve topressure changes. The valving channels or pathways are configured tocooperate with the associated valve seat so as to provide a smoothtransition of gas flow between open and closed positions of the valve.

The regulator valve is very small in size (typically about 1 in. by 2in. in diameter) and can provide regulated outlet-pressures as low as 1psi at inlet-pressures above 2000 psi. By making use of threadedhousings, fewer parts are required, and sub-assemblies can be used toimprove automation of assembly and cost effectiveness.

Other features and advantages of the invention will be apparent fromfollowing drawings and graphs.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred exemplary embodiments of the invention are illustrated in theaccompanying drawings in which like reference numerals represent likeparts throughout, and in which:

FIG. 1 schematically illustrates a typical dispenser in which aregulator valve constructed in accordance with the present invention maybe used;

FIG. 2 is a sectional side elevation view illustrating the gas regulatorvalve of FIG. 1 as a complete assembly;

FIG. 3 is a sectional side elevation view illustrating one of the threeunits that make up the regulator valve;

FIG. 4 is a sectional side elevation view illustrating another of thethree units that make up the regulator valve;

FIG. 5 is a sectional side elevation view illustrating still another ofthe three units that make up the regulating valve,

FIG. 6 is a partially exploded sectional side elevation view of thethree units that make up the regulating valve;

FIGS. 7 and 7A are a collection of sectional side elevation views of aportion of the regulator valve in its fully-closed position;

FIGS. 8 and 8A are sectional side elevation views of a portion of theregulator valve its half-open position;

FIGS. 9 and 9A are a collection of sectional side elevation views of aportion of the regulator valve in its full-open position;

FIG. 10 is an exploded side elevation view of the regulator valve; and

FIGS. 11 and 12 are a pair of graphs comparing operation of a regulatorvalve constructed in accordance with the invention to that of a priorart regulator valve

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings for a better understanding of theinvention, and more particularly to FIG. 1, a dispensing storagecontainer for liquids is shown generally at 1 and stores a potableliquid under a pressurized gas blanket or layer contained therein. A gassuitable for dispensing the liquid from the container may be carbondioxide or some other non-flammable gas such as nitrogen. The gas issupplied by a source 3 that may, for instance, comprise a commerciallyavailable CO₂ cartridge. The pressure in the container 1 is controlledby a pressure regulator valve shown generally at 2. The valve 2 isplaced between the dispensing container 1 and the source of pressurizedgas. The container 1 may comprise, e.g., a keg configured to dispense abeverage. It should be understood that the same valve 2 and other valvesconstructed in accordance with the present invention can be used in avariety of other applications including the dispensing of medicinalproducts, the dispensing of non-potable liquids, and any otherapplication requiring the dispensing of a liquid or gas at a designatedrate and/or a designated pressure.

Referring to FIG. 2, the valve 2 is formed from first, second, and thirdmain units that are attached to one another to form a completed assemblyin which a high pressure chamber 15 and a balance control chamber 33 aredisposed at opposite ends of the valve 2 with a low pressure chamber 22formed therebetween. The high pressure chamber 15 is connected to thehigh pressure source 3 via a hose or line connected to a threaded inlet13, and the low pressure chamber 22 is connected to dispensing container1 either by direct communication or an intervening line or hose. All ornearly all valve components preferably are made of a plastic or anotherengineered polymer such as Polysulfone®.

Referring to FIG. 3, the first unit of the valve 2 includes a firsthousing 5 and a sub-assembly 9, 10 screwed into threads 18 formed on theinner diameter of a bore formed in a generally central portion of thehousing 5. The sub-assembly 9, 10 includes 1) a seal holder 10 threadedinto a bore 34 in the housing 5 and 2) a seal 9. The seal 9 has aplastic overlay and an elastomeric lip seal which is of the typedisclosed in U.S. Pat. No. 5,645,192 and U.S. Pat. No. 6,109,485. Theseal 9 functions as a valve seat to seal-off high pressure chamber 15and high pressure source 3 from low pressure chamber 22 and container 1.A replaceable flow-rate outlet orifice part 20 is screwed intolow-pressure outlet threads formed in a radial bore 19 opening into thelow pressure chamber 22. The replaceable flow-rate outlet orifice part20 can house any of a variety of different orifices 21 that set the rateof flow out of the low-pressure chamber 22 at a desired value.

Referring to FIG. 4, the second unit of the valve 2 includes a secondhousing 4 having a sub-assembly 9, 10 mounted in a stepped bore 32formed in the housing 4. The bore 32 has an upper portion 23 and a lowerportion 37 separated by a flange 38. The sub-assembly 9, 10 is facedwith a keeper disk part 8 screwed into threads 23 in the inner end ofthe upper portion 23, which forms the inner end of a balance controlchamber 340 of the valve 2. The sub-assembly 9-10 is identical to thecorresponding sub-assembly of the first unit, hence permitting the useof interchangeable parts in the first two units. Another sub-assembly6-26 of the second valve unit faces a sub-assemble 7-27 screwed intothreads in the outer end 37 of the balance control chamber 33. Thesub-assembly 6-26 is formed from a cap seal 6 and an adjustment cap 26threaded into the bottom end 37 of the bore 32, and sub-assembly 7-27 isformed from a bias spring cap 7 and bias pressure spring 27 which biasesthe second unit towards the valve-open position.

Referring to FIG. 5, the third unit comprises a sub-assembly 11-17extending through the low pressure chamber 22 and into the high pressurechamber 15 and the balance control chamber 40. The sub-assembly 11-17comprises a diaphragm 11 and a rod tower 17 that together, form agas-balanced piston-tower valve part. The diaphragm 11 is bonded to rodtower 17 and has 1) an O-ring 30 portion formed or otherwise providedtherein. The rod tower 17 has an internal passage 16 formed therethroughend 2 a plurality of external graduated pathways 14 that selectivelypermit a controlled flow of high pressure fluid into the low pressurechamber 22 from the high pressure chamber 15 as detailed below. Thepathways 14 are formed from a plurality of peripherally-spaced groovesformed in the exterior surface of the rod tower. The depth of the upperend of each pathway 14 is tapered to provide smooth opening and flowrate control as detailed below.

The diaphragm 11 is clamped between the first and second housing 4 and 5of the first and second units seal the low pressure chamber 22 from thebalance control chamber 33. More specifically, referring to FIG. 6, theorientation of the third unit between the second unit and the first unitallows the capture and confinement of 0-ring portion 30 of diaphragm 11between sealing grooves 31 and 29, respectively, by screwing the femalethread 24 on the first housing 5 to the male thread 25 on the secondhousing 4. This orientation of the third unit requires the upper end ofrod tower 17 to pierce through the seal 9 of the first unit into thehigh pressure 15 and the lower end of the rod tower 17 to pierce throughthe seal of 9 of the second unit into the balance control chamber 33.

Operation

Referring again to FIG. 2, upon coupling the pressurized gas from source3 to the high high pressure chamber 15, gas flow will bifurcate at theupper end of rod tower 17 via the internal passage 16 and the externalpathways 14. The gas passing through passage 16 places the balancecontrol chamber 33 in constant fluid communication with the highpressure chamber 15, thereby negating any high-pressure thrust forcedifferential at the ends of rod tower 17. With little or nohigh-pressure thrust present on rod tower 17, the bias force of thespring 27 will have connective control over the free axial movement of agas-balanced piston-tower valve part 11-17 of the third unit against thevolume change of low-pressure chamber 22. The gas passing through theexternal pathways 14 will flow past the rod tower 17, into low pressurechamber 22, and into the container 1.

FIGS. 7B-9C collectively show the volume change of the exposed areas ofthe pathways 14 from open to mid to close. Detail view 9B shows thevalving-seat cross section of seal 9 at sealing-lip 12 and one quarterof whole valving pathway 14 of rod tower 17 when the valve 2 is in itsrest or full open position. As gas migrates past sealing lip 12, throughpathways 14, and into low-pressure chamber 22, gas pressure in lowpressure chamber 22 rises against confinement and forces diaphragm 11 toimpart downward axial movement onto rod tower 17. This axial movementwill begin to close off gas-flow from the source 3 by moving the rodtower 17 downwardly to a position in which only the upper tapered endsof the pathways 14 extend past the sealing lip 12. Detail view 8B showsthe mid point of this closure, and detail view 7B shows full gas cut-offwhich occurs when the sealing lip 12 seals against the rod tower 17above the pathways 14. The reduced gas flow rate by movement of the rodtower 17 and consequent reduction of pathway inlet area achieves balanceof the preset pressure in container 1 and cuts off gas-flow from thepressurized source 3.

The rate of gas flow into the low pressure chamber 22 is controlled bythe shape of the pathways 14, and numerous rates of flow can thereforebe defined with a gradual and progressive widening and deepening of thisshape along the length of the rod tower as the rod tower 17 seals to lip12 from full open to close. The gas flow rate variation with rod towermovement is very smooth and sensitive as compared to a standard popopen/pop-close valve.

The graphs of FIGS. 11 and 12 show the relationship of gas-flow of theillustrated embodiment of the invention curve 50 in. (FIG. 11) ascompared to a standard regulator employing a poppet valve curve 52 in.(FIG. 12). The operating curves are plotted using cross sectional squarearea (in²) of exposed gas pathway found at a given axial stroke of valveelement movement in (thousands of an inch) as the valve opens andcloses. The curve 50 of FIG. 11, illustrating operation of theembodiment of the invention described above, is smooth and gradual,showing that flow rates vary gradually with stroke. The curve 52 of FIG.12, illustrating operation of a standard poppet valve seat, is verysharp because the valve is either fully open or fully closed. The dataplotted by these cures is reproduced by the following tables:

TABLE 1 FLOW CHARACTERISTICS OF REGULATOR WITH INVENTIVE VALVE Rod towerstroke distance (in) Pathway cross sectional flow area (in²) 0.140.000188 0.13 0.000188 0.12 0.000188 0.11 0.000188 0.1 0.000188 0.090.000188 0.08 0.000169 0.07 0.000134 0.06 0.000115 0.05 0.000096 0.040.000063 0.03 0.0000321 0.02 0.0000104 0.01 0.0000054 0 0

TABLE 2 FLOW CHARACTERISTICS OF REGULATOR WITH POPPET VALVE Rod towerstroke distance (in) Pathway cross sectional flow area (in²) 0.140.000188 0.12 0.000188 0.11 0.000188 0.1 0.000188 0.09 0.000188 0.080.000188 0.07 0.000188 0.06 0.000188 0.05 0.000188 0.04 0.000188 0.030.000188 0.02 0 0.01 0 0 0

While a preferred embodiment of the present invention has beenillustrated in detail, it is apparent that modifications and adaptationsof the preferred embodiment will occur to those skilled in the art, andit is to be expressly understood that such modifications and adaptionsof the preferred embodiment will occur to those skilled in the art.However, it is to be expressly understood that such modifications andadaptations are within the spirit and scope of the present invention asset forth in the following claims.

1. A regulating valve as comprising (A) a housing which has a highpressure chamber and a low pressure chamber formed therein; (B) a valveseat which is disposed in said housing between said high pressurechamber and said low pressure chamber; and (C) a valve element which isdisposed in said housing and which is selectively movable, upon apressure drop in said low pressure chamber beneath a designated pressurethrough a valve opening stroke extending between 1) a fully closedposition in which said valve element seals against said valve seat toprevent fluid flow from said high pressure chamber to said low pressurechamber, and 2) a fully open position in which a maximum inlet flow areaof said valve element is open to permit fluid to flow from said highpressure chamber to said low pressure chamber at a maximum rate, andwherein said inlet flow area of said valve element increasescontinuously for at least a substantial portion of the opening stroke ofsaid valve element so that the rate of fluid flow through said valveincreases throughout said substantial portion of the valve elementstroke, wherein, during the valve opening stroke, a flow rate from saidhigh pressure chamber to said lower pressure chamber varies at leastgenerally proportionally with the pressure drop in said low pressurechamber through at least a substantial portion of the valve openingstroke of said valve element, wherein said regulating valve comprisesthree modular units one of which includes a diaphragm trapped betweenthe other two units, and wherein the other two units each include a sealholder threaded into a bore in a valve body and an annular lip sealmounted in said holder in sliding contact with said valve element.
 2. Aregulating valve as recited in claim 1, wherein said seal holders areidentical to one another and said lip seals are identical to oneanother.
 3. A regulating valve comprising: (A) a housing in which isdisposed a high pressure chamber, a balance control chamber in constantfluid communication with said high pressure chamber, and a low pressurechamber disposed between said high pressure chamber and said balancecontrol chamber; (B) a valve seat which is disposed in said housingbetween said high pressure chamber and said low pressure chamber, saidvalve seat comprising an annular lip seal having an axially sealingsurface and a radially sealing surface; and (C) a valve element which isdisposed in said housing, said valve element comprising (1) a rod towerwhich, in response to a pressure drop in said low pressure chamberbeneath a designated pressure, is movable axially within a valve bodythrough a stroke that is at least generally proportional to the pressuredrop in said low pressure chamber and which has an outer radialperipheral surface in sliding contact with said radially sealing surfaceof said lip seal, said rod tower being between 1) a fully closedposition in which said rod tower seals against said radially sealingsurface of said lip seal to prevent fluid flow from said high pressurechamber to said low pressure chamber, and 2) a fully open position inwhich a maximum inlet flow area of said valve element is open to permitfluid to flow from said high pressure chamber to said low pressurechamber at a maximum rate, and wherein, during said rod tower movement,a flow rate from said high pressure chamber to said low pressure chambervaries with the pressure drop in said low pressure chamber through atleast a substantial portion of the opening stroke of said valve element,wherein said inlet flow area of said valve element increasescontinuously for at least a substantial portion of the opening stroke ofsaid rod tower movement so that, through said substantial portion, therate of fluid flow through said valve is at least generally proportionalto the magnitude of said rod tower from said fully closed position,wherein said inlet flow area is defined by a plurality of pathways onsaid rod tower that have a combined cross sectional area that variesalong an axial dimension of said rod tower, (2) a diaphragm to whichsaid rod tower is connected and which flexes in response to pressuredrops in said low pressure chamber to drive said rod tower to moverelative to said valve seat from said fully closed position to saidfully open position, and (3) a spring which biases said rod towertowards the fully-closed position thereof.
 4. A regulating valve asdefined in claim 3, wherein at least inlet ends of said pathways aretapered circumferentially and inclined relative to the axis of said rodtower.
 5. A regulating valve as defined in claim 3, wherein: (A) saidregulating valve comprises three modular units one of which includes adiaphragm trapped between the other two units, wherein (B) the other twounits each include a seal holder threaded into a bore in said valve bodyand an annular lip seal mounted in said seal holder in sliding contactwith said valve element, and wherein (C) said seal holders are identicalto one another and said lip seals are identical to one another.
 6. Aregulating valve as recited in claim 3, wherein said rod tower has apassage formed therethrough connecting said high pressure chamber tosaid balance control chamber.
 7. A method of assembling a pressureregulating valve, comprising: (A) providing a valve housing having ahigh pressure port, a low pressure port, and an interior; and (B)mounting a valve assembly in said interior of said valve housing so asto divide said valve housing into a high pressure chamber, a balancecontrol chamber in constant fluid communication with said high pressurechamber, and a low pressure chamber disposed between said high pressurechamber and said balance control chamber, said valve assembly includingfirst and second seal assemblies disposed in opposite end portions ofsaid valve housing and being of identical construction.
 8. A method asrecited in claim 7, wherein each of said first and second sealassemblies comprises 1) a seal holder screwed into a threaded bore insaid valve housing and 2) an annular ring seal retained in said valvehousing by said seal holder, and wherein the mounting step comprisesmounting identical ring seals in the associated seal holders in inverseorientations relative to one another.
 9. A method as recited in claim 7,further comprising mounting a restrictor having a first coefficient offlow restriction in a low pressure port of a valve body and subsequentlyreplacing said first restrictor with a second restrictor having a secondcoefficient of flow restriction.
 10. A method as recited in claim 7,wherein the providing step comprising providing a valve housing formedfrom first and second housings sections screwed together with a valveelement of said valve assembly clamped therebetween.